//: C15:Wind2.cpp
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 1999
// Copyright notice in Copyright.txt
// Inheritance & upcasting
#include <iostream>
using namespace std;
enum note { middleC, Csharp, Cflat }; // Etc.

class Instrument
{
public:
    void play(note) const {
        cout << "Instrument::play" << endl;
    }
};

// Wind objects are Instruments
// because they have the same interface:
class Wind : public Instrument
{
public:
    // Redefine interface function:
    void play(note) const {
        cout << "Wind::play" << endl;
    }
};

void tune(Instrument& i)
{
    // ...
    i.play(middleC);
}

int main()
{
    Wind flute;
    tune(flute); // Upcasting
} ///:~
